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Biomedical subjects

G Cross

Publications and source records attributed to G Cross.

At least 37 records · Page 2Linked to original sources

A comparison of epidural diamorphine with intramuscular papaveretum following caesarean section.

Following caesarean section carried out under epidural blockade using local anaesthetic only, 40 consenting women were randomly allocated to receive either epidural diamorphine 2.5-5 mg in 10 ml physiological saline and intramuscular saline or epidural saline and intramuscular papaveretum 10-20 mg, dosage depending on weight, when the pain returned. When analgesia was next requested the alternative treatment was given. A visual analogue pain score was recorded before and 15, 30, 60, 120, 180 and 240 min after the first treatment. Respirations were counted and symptoms noted. On the following day the mother was asked whether she preferred the first or the second treatment. Both treatments produced a reduction in pain score but analgesia was significantly better with epidural diamorphine and the duration of action (8.5 +/- 5.2 h) was significantly longer than that following intramuscular papaveretum (4.1 +/- 2.3 h, P < 0.01). Two mothers who received epidural diamorphine initially required no further analgesia. No difference in respiratory rate was noted but side-effects were more frequent with epidural diamorphine. Despite this more women preferred this treatment. Because of enhanced mobility provided by good analgesia epidural diamorphine is worth offering to women following caesarean section.

Journal Article↗

Haemodynamic adjustments to mental stress in normotensives and subjects with mildly elevated blood pressure.

Cardiac output, heart rate, stroke volume, pre-ejection period, total peripheral resistance, systolic and diastolic blood pressure, and oxygen consumption were monitored or derived in young men with mildly elevated casual blood pressures and unambiguously normotensive control subjects before, during, and after exposure to a mental arithmetic stress. Measurements were also taken while subjects underwent graded dynamic exercise. This permitted cardiac output-oxygen consumption regression equations to be calculated and, as a consequence, cardiac output during mental stress to be represented as additional cardiac output. Systolic and diastolic blood pressure were higher during all phases of the study in the mildly elevated blood pressure group. An overall groups effect during the mental stress phase of the experiment was observed for cardiac output and pre-ejection period, and the effect for stroke volume was close to significance. Significant Groups X Periods interactions were found for cardiac output and additional cardiac output, and the heart rate effect was nearly significant. Post-hoc comparisons here indicated that, in the main, group differences in these cardiac variables were more evident during the mental arithmetic stress than during the pre- and post-task baseline periods. Total peripheral resistance did not differ reliably between groups and the cardiac effects were specific to the mental stress phase of the study.

Adult↗

Atropine-induced heart rate changes: a comparison between midazolam-fentanyl-propofol-N2O and midazolam-fentanyl-thiopentone-enflurane-N2O anaesthesia.

Atropine-induced heart rate (HR) changes were studied in 19 patients (ASA physical status I) during anaesthesia-maintained predominantly with propofol-N2O or thiopentone-enflurane-N2O. Ten patients (Group A) received midazolam (0.07 mg.kg-1), fentanyl (1 microgram.kg-1), propofol (2 mg.kg-1) and succinylcholine (1 mg.kg-1). Following tracheal intubation, anaesthesia was maintained with propofol (6 mg.kg-1.hr-1), N2O (67 per cent) and O2 (33 per cent). In nine patients (Group B) thiopentone (4 mg.kg-1) was substituted for propofol and anaesthesia maintained with N2O (67 per cent) O2 (33 per cent), and enflurane (0.5 per cent inspired concentration). The study was non-randomised because Group B patients were only included if HR before administration of atropine less than 90 beats.min-1. IPPV was performed in all patients using a Manley ventilator (minute vol. 85 ml.kg-1; tidal vol. 7 ml.kg-1). Ten minutes after tracheal intubation, incremental doses of atropine (equivalent cumulative doses: 1.8, 3.6, 7.2, 14.4, 28.8 micrograms.kg-1) were administered at two-minute intervals and HR responses calculated during the last 45 sec of each intervening period. No differences were observed between the groups following 1.8 and 3.6 micrograms.kg-1 atropine, but propofol-N2O anaesthesia was associated with reduced responses (P less than 0.01) following 7.2, 14.4 and 28.8 micrograms.kg-1 atropine. These results suggest that there is a predominance of parasympathetic influences during propofol-N2O anaesthesia compared with thiopentone-enflurane-N2O anaesthesia.

Adult↗

An analgesiometry system for use in rabbits with some preliminary data on the effects of buprenorphine and lofentanil.

A low cost infrared skin heating system has been designed to measure the efficacy of analgesics in rabbits. Following construction of a prototype, it was used to assess the effect of buprenorphine given subcutaneously and per rectum. Buprenorphine administered subcutaneously has a rapid onset of action, but its duration (8-10 h) appears slightly shorter than has been suggested previously; rectal administration appears to prolong its effect. Preliminary data show that lofentanil has a longer duration of action than buprenorphine and it may prove, therefore, to be a valuable long-acting analgesic in the rabbit.

Analgesia↗

Inferior pulmonary ligament lymphadenopathy: demonstration by computed tomography.

Inferior pulmonary ligament lymphadenopathy is common in bronchogenic carcinoma and may also occur in lymphoma and potentially in any condition which may cause intrathoracic lymphadenopathy. Despite the apparent frequency with which inferior pulmonary ligament lymphadenopathy occurs, we have been unable to find a description of the computed tomographic findings of this condition. In a patient with lymphoma, we found inferior pulmonary ligament lymphadenopathy by computed tomography as an oval, elongated soft-tissue density arising within the inferior pulmonary ligament and still attached to the mediastinum by a piece of the normal ligament. We believe that this appearance should be sufficient for the correct computed tomographic diagnosis of inferior pulmonary ligament lymphadenopathy.

Aged↗

Prognosis for babies born with fused eyelids.

The overall mortality for babies referred to our unit with fused eyelids was 68.7%; but when severe skin bruising was present only one of 18 babies survived (5.6%). This compares with a survival rate of 75% for those not bruised at or soon after birth. Skin bruising invariably indicates a very poor prognosis in babies born with fused eyelids.

Contusions↗

Transcutaneous aortovelography. A quantitative evaluation.

The haemotachograph is a non-invasive ultrasonic Doppler-shift instrument designed to measure the velocity of blood in the arch of the aorta by a technique referred to as transcutaneous aortovelography. Its accuracy has been assessed at cardiac catheterization in 20 patients. When transcutaneous aortovelographic values were compared with stroke volume determined by standard invasive techniques, a good proportional agreement was found. The accuracy of absolute flow values, as calculated from transcutaneous aortovelography and dimensional data, was, however, poor. Peak velocity determined from transcutaneous aortovelographic tracings agreed well with values obtained with a catheter tip electromagnetic velocity probe. Transcutaneous aortovelography is a useful non-invasive technique which can be used to determine phasic blood flow velocity in the aortic arch and to follow changes in cardiac output over a period of time.

Adult↗